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Sunday, May 19, 2013

Wilson Avenue - one of Chicago's Water Intake Crib Lights

The City of Chicago's originally pulled its
water from the Chicago River, but with rapid growth around the river
combined with the river serving as a convenient dumping place for the
city’s waste, it was not long before the river became a virtual open
sewer.

The Chicago River near the turn of the nineteenth century

In
order to obtain fresh water, the city of Chicago began pumping water
from the harbor. However, the waters near shore soon became too polluted
to use, and in 1865 the City established a large timber crib out in
Lake Michigan where water was collected and pulled through a hand-dug
tunnel beneath the lake to a pumping station on shore. The structure was
known as the Two Mile Intake Crib by virtue of its location two miles
offshore. As can be seen in this contemporary lithograph, by virtue of
its location in the lake, the structure was outfitted with a lantern and
served as an aid to navigation both warning of its presence and guiding
mariners into the harbor.

Lithograph of Chicago's Two Mile Crib

As
the great city of Chicago grew over the ensuing years, a number of
additional water intake cribs and their connecting tunnels to shore were
built off the harbor. One of these structures was known as the Wilson
Avenue intake crib as a result of its tulle system connecting to a new
pumping station at the foot of Wilson Avenue. Work on crib began in 1915
with the sinking of a steel caisson having a
diameter of ninety feet. Built using square-hewn granite blocks, the
superstructure served to protect a forty-foot diameter inner well
chamber and as housing for the city employees who staffed the plant and
tended the light that would be erected at the center of its roof. The photograph below shows work progressing on erecting the granite walls of the structure.

Construction underway on the Wilson Avenue water intake crib

All
told, the Wilson Avenue Intake Crib supplied eight miles of water
tunnels, which were hand-dug through the bedrock beneath Lake Michigan -
a tremendous feat of engineering and back-breaking labor. This 1916
photograph shows the interior of one of these tunnels after completion.

Inside one of the Wilson Avenue Water Intake Crib tunnels

When
they were approximately half way through the construction of the Wilson
Avenue intake crib in Chicago, the Engineers found that the caisson had
settled, causing the superstructure to be sitting a few degrees from
horizontal. Holes were bored beneath the low side of the caisson and
hydraulic cement was pumped into them, lifting the structure back to the
correct orientation. This photograph taken in 1916 shows one of the
engineers on a platform which was erected in the center of the
superstructure, using a theodolite to ensure the top surface of the
granite walls had been brought back to horizontal.

Engineer checking the structure for level

This
photograph from a 1926 edition of Popular Science magazine was taken
from a Water Department supply tug approaching the Wilson Avenue intake
crib in winter.

The Wilson Avenue Intake Crib in wither

Winter
was a particularly difficult time for the crews stationed on Chicago's
intake cribs, as they had to toil with picks and poles to prevent ice
from building to the point that it clogged the main intake at the center
of the well room within the structure, as seen in this 1926 photograph.
When the temperature plummeted to sub zero levels, and ice formed thick
and fast, small dynamite charges were used to break the ice to keep the
water flowing. A dangerous, but necessary remedy in such a confined
location.

Removing ice from the water intake

Crews
at Chicago's intake cribs not only had to contend with their water
department duties, but they also had to maintain the aid to navigation
atop the center of the crib. Here we see one of the crew members
cleaning the lantern glass atop the Wilson Avenue intake crib.

cleaning the lantern glass atop the Wilson Avenue intake crib.

In
a manner similar to that adopted at offshore lighthouses, Chicago's water intake cribs
were staffed by four to five man crews with one man on a week's shore
leave every fourth or fifth week. Supplies and crews were transported to
and from the cribs by Water Department tugs, as seen in this 1950
photograph from one of the tugs approaching the Wilson Avenue Crib.

A crew swap by Water Department tender at the Wilson Avenue Water Intake Crib

While
working Chicago's water intake cribs could at times be a back-breaking
job, the living conditions were good with fairly expansive quarters and
all conveniences of the day. This photograph taken at the 68th Street
Intake Crib shows the crew gathering for Thanksgiving dinner. From the
manner of their dress, we can discern that their quarters were well
heated, and their girth hints that they certainly were not short of
food! Crews continued to man the intake cribs until the 1990's, when the
decision was made to maintain them from shore.

Thanksgiving dinner at one of Chicago's Water Intake Cribs

This
photograph of the Wilson Avenue water intake crib was taken in 2010
during our Southern Lake Michigan Excursion, and shows the wonderful
vista city that would have tantalized the crib tenders when they were
still assigned there. Since "9/11" the cribs intake are considered to be
a target for terrorism, and there are sophisticated surveillance
systems installed all around them along with numerous
"Keep Off" signs posted. The good folks of Chicago see this cribs out
in the lake, but precious little is known of them. In 2007, the Chicago
Tribune approached the Water Department seeking permission to visit the
cribs as part of their "Unauthorized" series in which they visit places
around in the Metro area which are normally closed to public access.
However, the cribs are considered so sensitive that their request was
flatly denied.

The keepers on Chicago's Intake Cribs had a tantalizing view of the city skyline

As
can be seen in the photograph below from 2010. the glass has been removed
from the lantern atop Chicago's Wilson Avenue water intake crib, and as
is the case with most historic maritime structures, the structure now
serves as a roost for a huge flock of cormorants and gulls. The
structure still serves as an active aid to navigation and in 2010 was
lighted by a Tideland Signal 300mm optic powered by city electricity
supplied by a submarine cable.